1. Field of the Invention
The present invention relates to a device for controlling the feeding quantity of a sewing machine.
2. Description of the Related Art
A conventional device of the type is disclosed, for example, in Japanese Utility Model Publication 57-13005 published in 1982. In the conventional device, two cloth layers to be sewn are respectively fed by an upper feed-dog and a lower feed-dog. The feeding quantity of the upper feed-dog is the same as that of the lower feed-dog under the normal operation mode sewing.
However, in the conventional device, when the feeding quantity of the upper feed-dog has to be changed due to a change of the needle-numbers, a changing or adjusting operation of the feeding quantity of the upper feed-dog and a changing or adjusting operation of the feeding quantity of the lower feed-dog have to be separately performed. Such operations are cumbersome for an operator of the machine.